Waste collection system for collecting solid medical waste including a loading station with a metal detection sensor and/or a bag-tensioning mechanism

ABSTRACT

A solid medical waste collection system for collecting solid medical waste. The system includes a mobile cart with a bag for storing the waste. A pre-detection apparatus detects metal-containing objects prior to placing them inside the bag to reduce costs to the facility in which the cart is employed. The system may also include a bag-tensioning mechanism for securing the bag to the cart.

RELATIONSHIP TO EARLIER FILED APPLICATIONS

This application is a continuation of PCT App. No. PCT/US2009/045668filed 29 May 2009. PCT App. No. PCT/US2009/045668 is a non-provisionalof U.S. Provisional Pat. App. No. 61/057,666 filed 30 May 2008. Theearlier filed applications are incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates generally to a system for collecting andtemporarily storing solid medical waste. More particularly, the presentinvention is directed to a system comprising detection features forreducing inadvertent disposal of reusable medical equipment, tools, andaccessories and bag retention features for securing bags to carts usedfor collecting waste.

BACKGROUND OF THE INVENTION

When a medical or surgical procedure is performed solid waste istypically generated. Generally, this type of waste falls into one ofseveral categories. First, there is conventional trash. This type ofwaste includes solid articles such as paper, plastics and otherpackaging material that is not contaminated with tissue or bodilyfluids. This waste is typically deposited in white or clear bags. Asecond type of waste, although not truly “waste”, is the linens, towelsand sheets used during the procedure. These linens, towels and sheets,are used for such purposes as stabilizing the patient, draping offportions of the patient, or cleaning up liquids. Often these materials,even those covered in bodily fluids, can be cleaned, sterilized, andreused. This type of waste is typically deposited in green bags. A thirdtype of solid waste includes solid articles that, during the procedurebecome coated or exposed to bodily fluids. These articles includedisposable wipes, gloves and drapes used at or around the surgical siteas well as single use disposable medical instruments. Post use, thesearticles are disposed of in a manner that ensures the biologicalmaterial they carry does not serve as a source of infection. It is alsoimportant to prevent contamination of medical personnel and the medicalfacility when handling or transporting those waste materials. Often,this material is called “red bag” waste because it is typicallydeposited in specially marked red bags. A fourth type of solid waste isradioactive waste typically deposited in yellow bags.

During the course of a procedure, solid medical waste is deposited inthe corresponding bags secured to portable carts in the operating roomor other space in which they are generated. In some medical facilities,separate carts are provided for collection and storing the differenttypes of medical waste as described above. The circulating nurse orother individual responsible for initially disposing of the waste,initially categorizes the waste and places the waste in the appropriatebag on a cart. When a bag containing either conventional waste, red bagwaste, or radioactive waste is at or near capacity, it is sealed. Atthat time, the bag is transported to a loading dock for eventualtransport to a waste processing facility. Green bag waste is transportedto a processing facility where the linens, towels and sheets are cleanedand sterilized for reuse.

With the advent of packaged sterile goods, the amount of solid medicalwaste generated has increased. This is particularly true of packagedsterile equipment that takes the place of a reusable piece of equipment,tool, or accessory. The acceptance of packaged sterile goods and newmedical technologies and procedures has increased the amount and bulk ofmaterials entering the waste stream. This has also increased the chancesof reusable medical equipment inadvertently entering the waste stream.Specifically, budgets for purchasing lost reusable equipment haveincreased over time due to the reusable equipment being lost orinadvertently thrown away. When certain high value medical equipment hascome up missing, some hospitals have mandated that their workers dophysical searches of bags of trash entering the waste stream with hopesto find the lost equipment. This solution is not practical, notdesirable and also possesses risks to the workers assigned to find theequipment. One important risk involves the exposure of the worker tobiologically contaminated waste when searching the “red bag” forinadvertently lost equipment.

A reusable medical device, due to its service life expectations,contains durable components, many of them metal. As a result, suchequipment can be detected with appropriately designed metal detectionsystems. The metal detection system then alerts the worker that ametal-containing piece of equipment, tool, or accessory has beendeposited in a waste bag.

Metal detection systems are available in many different forms and can beused to assist a searcher in finding lost metallic items. Some systemsemploy a metal detector for detecting metal after the waste bags havebeen filled with waste. The obvious shortcomings of these systemsinclude requiring workers to maneuver often heavy, full bags of trash.What's more, if metal is detected, the worker must then rummage througha full bag of trash to uncover the item. Many times the item found inthe trash was a single use disposable manufactured with metalliccomponents and therefore may have been correctly deposited in the bagafter all. For instance, there are several single use disposable itemswith metallic components like motors or batteries that will be detected.Additionally, the bags are usually tied shut and are difficult to openmaking the worker's task even more difficult.

Further, it should be appreciated that biological materials can includecontaminates and transmit infectious diseases. Accordingly, theindividuals handling bags containing these materials run the risk ofinadvertent exposure to these contaminates. Also, an appreciablefraction of these biological materials are in the liquid state. Thesefluids have been known to leak out of a bag during handling. Also, whenin the liquid state, these biological materials, and their associatedcontaminates, have been known to become aerosolized. When this happensthe surrounding environment can become contaminated which increases therisks of transmission to more persons other than those responsible forhandling the bags. These hazards considerably increase when workerssearch for reusable equipment or other metallic items mixed ininfectious or hazardous waste.

Another proposed solution is metal detection at the point of disposal.Known waste carts typically include a barrel for holding the waste bagsand a metal detector ring for placing on top of the barrel over the bag.In these systems, when a metal-containing object is discarded, an alarmis tripped requiring the user to look inside the bag for themetal-containing object. As previously described, this is less thandesirable during a medical or surgical procedure. If the bag ispartially or nearly full of medical waste, the metal-containing articlemay slip to the bottom of the waste bag when the worker shifts themedical waste in the bag looking for the metal-containing object.Additionally, sterile personnel performing a medical procedure cannotsearch the contents of the waste containers without breaking sterility.

Since the metal detector ring accumulates dust and biological materialsdue to the medical detector ring being on top of the barrel and wastebag, the metal detector ring must be cleaned between uses. Also, metaldetection on these prior art systems may not be tunable to vary theamount of metallic content that triggers the alarm. Thus, with theincrease in disposable medical equipment, tools, and accessories, someof these prior art systems are unable to selectively set alarmconditions and reduce false alarms.

Securing waste bags to conventional waste carts is often cumbersome.Some workers tie a knot in the top of the waste bag to reduce the sizeof the opening. The bag is then stretched over a hoop of the waste cartto secure the bag to the waste cart. This method is time consuming andnot always predictable.

The Applicants' Assignee's U.S. Provisional Patent Application No.60/980,964, SYSTEM AND METHOD FOR COMPACTING SOLID MEDICAL WASTE, filed18 Oct. 2007, the contents of which are contained in PCT App. No.PCT/US2008/080170, filed 16 Oct. 2008, published as WO 2009/052291 A1and US Pat. Pub. No. US 2010/0201090 A1, both of which are herebyincorporated as reference, discloses one alternative system forcollecting medical waste and, during the collection process, determiningif an article formed from metal is being inadvertently discarded.

However even the above system has disadvantages associated with its use.These disadvantages are associated with how a bag is secured to theframe of the system of WO 2009/052291 A1 and US Pat. Pub. No. US2010/0201090 A1 and how this system informs medical/surgical personnelthat a metal item may have been inadvertently discarded.

SUMMARY OF THE INVENTION

This invention is directed to a new and useful system for holding solidwaste such as the waste generated during a medical/surgical procedure.The system of this invention includes a mobile base that holds a bag forcollecting waste. In some versions of the invention, a frame, from whichthe bag is suspended, contains a sensor assembly for detecting if metalobjects are passed through the open end of the bag. A processor monitorsthe signals emitted by the sensor. In the event the sensor signalsindicate an article with a substantial content of metal is placed in thebag, the processor actuates both an audible alarm and a light. Theaudible alarm is actuated only for a short time. The light is actuateduntil the system is reset by the medical/surgical personnel.

The system of this invention also includes a tensioner that holds thebag tight to the frame. When it is desired to remove the bag, thetensioner is released.

In some versions of this invention, the cart has an escrow hold. Thewaste is placed in initially placed in the escrow hold. Sensors aroundthe escrow hold determine if the waste contains metal. If there is nometal in the waste, the waste is automatically transferred to the bag.Alternatively, if sensors detect the presence of waste in the escrowhold, the alarms are actuated. This provides the personnel theopportunity to remove any metal objects that may have inadvertentlyplaced in the system.

BRIEF DESCRIPTION OF THE DRAWINGS

Advantages of the present invention will be readily appreciated as thesame becomes better understood by reference to the following detaileddescription when considered in connection with the accompanying drawingswherein:

FIG. 1 is a perspective view of a cart of the present invention, theview being of the front of the cart;

FIG. 2 is a block diagram of the electrical components integral with thecart;

FIGS. 3 and 4 are flow charts depicting steps taken for weight detectionand metal detection;

FIG. 5 is a front perspective view of a cart of the present inventionwith a pre-detection apparatus;

FIG. 6 is a side elevational view of the cart of FIG. 5;

FIG. 7 is a perspective view of a protective covering for use with ahopper of FIG. 5;

FIG. 8 is a perspective view of an alternative bag/covering for use withthe cart and hopper of FIG. 5;

FIG. 9 is a side perspective view of a frame of the cart of the presentinvention, the cart be outfitted with another pre-detection apparatus;

FIG. 10 is a side perspective view of a portion of the frame of the cartoutfitted with another pre-detection apparatus of this invention;

FIG. 11 is a front perspective view of the cart with anotherpre-detection apparatus;

FIG. 12 is a side perspective view of a bag and bag-constraining deviceused with the cart of FIG. 11;

FIG. 13 is a top view of the bag-constraining device;

FIG. 14 is a front perspective view of the cart with anotherbag-constraining device comprising pivoting pinch bars;

FIG. 15 is a front elevational view of the bag of FIG. 14 illustratingthe pinch bars in a load position;

FIG. 16 is a front elevational view of the cart of FIG. 14 illustratingthe pinch bars in a dump position;

FIG. 17 is a front perspective view of another cart with yet another bagconstraining assembly comprising pivoting doors;

FIG. 18 is a front perspective view of an alternative cart with amovable platform and pinch bar assemblies with heat-sealing coils tosegment the bags into separate sealed batches of waste;

FIG. 19 is an elevational view of the pinch bars and drive assembly ofthe cart of FIG. 18;

FIG. 20 is a front elevational view of the cart of FIG. 18 illustratingseveral sealed batches of waste;

FIG. 21 is a front perspective view of another cart outfitted with aconveyor belt for moving waste through a metal detector frame and intothe bag;

FIG. 22 is a front partially perspective view of a bag-tensioningmechanism of the cart of FIG. 1;

FIG. 23 is a front perspective view of an alternative bag-tensioningmechanism with a sliding pin for placing tension on a periphery of thebag;

FIGS. 24A, 24B and 25 are front perspective views of further alternativebag-tensioning mechanisms utilizing flexible gripping pads for grippingthe bag to hold its tension on the frame of the cart; and

FIG. 26 is a top perspective view of yet another bag-tensioningmechanism comprising spring-biased swing arms.

DETAILED DESCRIPTION

Referring to the Figures, wherein like numerals indicate like orcorresponding parts throughout the several views, a solid medical wastecollection system is generally shown at 40 in FIG. 1. The system isparticularly adapted for collecting solid medical waste during medicalor surgical procedures, but is not limited to this purpose. Such wastemay include: (1) conventional trash; (2) used linens, towels and sheets;(3) solid articles coated or exposed to bodily fluids; (4) andradioactive waste.

Referring to FIG. 1, the system 40 comprises a cart 42 with a planarbase 44. Casters 46 are mounted to a bottom of the base 44 to providethe cart 42 with mobility. A rectangular leg 48 extends upwardly fromone side of the base 44. The leg 48 suspends an open rectangular frame50 above the base 44.

The frame 50 is formed from plastic or other material that does notaffect the transmission of electromagnetic waves. The frame 50 comprisesfront 60 and rear 62 webs and front-to-rear extending lateral webs 64,66 interconnecting the front 60 and rear 62 webs. The front 60 and rear62 webs of the frame 50 are longer than the associated front-to-rearextending lateral webs 64, 66.

A plurality of corner blocks 52 are mounted to the corners of frame 50.Each block 52 has at least one outer surface (not identified) that stepsoutwardly from the adjacent outer surface of the frame 50. The blocks 52act as retaining members that hold an open top portion of the bag 54,the peripheral section 51 of the bag 54, around the outer surface theframe 50. When the peripheral section 51 of the bag 54 is stretched andfolded over the outer surface of the frame 50 and the blocks 52, theperipheral section 51 is held under the blocks 52. The blocks 52protrude outwardly from corners of intersecting, adjacently connectedwebs 60, 62, 64, 66. Blocks 52 do not extend the full top-to-bottomlength of the frame 50. Thus, as seen in FIG. 17, when the bagperipheral section 51 is folded over the frame, this section of the bagis folded against sections of the outer surface of the frame belowblocks 52.

The bag 54 is preferably formed from a plastic that creates an air-tightbarrier. Plastics from which the bag 54 can be formed includepolyethylene, polypropylene or nylon. The bag 54 is formed to have twoopposed rectangular body panels 120. Bottom and side edges of the bodypanels 120 are sealed together.

In some embodiments, the base 44 includes a pressure sensitivetransducer 55 for determining a weight of the bag 54 as the bag 54 isfilled with waste. This feature and a base incorporating this featureare described in the incorporated by reference WO 2009/052291 A1 and USPat. Pub. No. US 2010/0201090 A1.

Metal detection coils in some embodiments of this invention are arrangedwith detection coil 72 and null coil 73 that are together oppositelydisposed to transmit coil 70. According to FIG. 1, these coils 70, 72,73 can be disposed in either the front 60 and rear 62 webs or thelateral webs 64, 66 given their opposing orientation. Collectively,coils 70, 72, 73 function as an emitter and sensor assembly that detectswhen metal is placed through the opening formed by the webs and into thebag 54. Generally, it should be understood that the signal output bydetection coil varies with the amount of metal that passes through frame60 into the open periphery 51 of bag 54. The above embodiment isdifferent than traditional metal detection coil arrangements.

Traditional metal detection coil arrangements can also be implementedinto a cart with suitable geometry. One coil arrangement, called aco-axial arrangement. In the co-axial arrangement, the coils are ofsimilar outside size and shape. The coils 70, 72 and 73 are coaxiallyaligned and are stacked one on top of the other. The coils are typicallyarranged with the null coil 73 on top, the transmit coil 70 in themiddle and the receive coil 72 on the bottom. These coils are wound incontinuous loops with the loops taking a range of shapes like circle,square, rectangle, triangle or hexagonal. In the co-axial arrangement,objects to be detected pass through the inside perimeter of the loopshape. Another coil arrangement known in the art is called concentriccoils. In the concentric coil arrangement, the coils typically align tothe same axis, but the sizes of the coils are different. In a typicalconcentric coil arrangement, the center loop coil is the null coil 73,the middle loop is the transmit coil 70 and the outer loop is thedetection coil 72. These coils of different perimeter sizes aretypically arranged in a planar fashion. This coil arrangement is usefulwhen trying to detect metal that is passed either over or under theplane formed by the concentric perimeters. The perimeter of theconcentric coils can also have a different shape such as circular,square, oval or triangular, with the most common shape being circular.

FIG. 2 is a block diagram of circuit components integral with the cart42. These components include a processor 74. A signal generator 76generates the AC signal that, as illustrated in FIG. 2, is applied toboth the transmit coil 70 and the null coil 73. The signal applied tonull coil 73 is typically out of phase with the signal applied to thetransmit coil so as to normally cancel out the signal output by thetransmit coil 70. Unless metal, when passing through the frame 50disrupts both signals, ideally no signals are developed across detectioncoil 72. Cart 42 also has a display 78. In some embodiments anenunciator 75, e.g., an audible alarm, is integral with the display 78.In some embodiments of the invention, one or more separately actuatedlights 79 are attached to the corners of the frame 50 and form part ofthe display 78.

In some embodiments, a light bar 85, seen in FIG. 1, with a plurality ofseparately actuated light segments 87 indicates the strength of thesignal generated by detection coil 72. While not shown, it should beunderstood that processor 74 regulates the actuation of the lightsegments 87. In some configurations of this invention, the number oflight segments 87 processor 74 actuates is proportional to the amount ofmetal detected passing through the frame 50 as determined based on theanalysis of the signal output by detection coil 72. Only one segment 87is illuminated if signal analysis indicates only a small amount of metalis passed into the bag 54. Plural light segments may be illuminated ifsignal analysis indicates that there may have been a large amount ofmetal placed in the bag. This feature is useful to quickly review therelative metal content of the objects being discarded in the bag 54.

The user sets the threshold of detected metal at which the alarm shouldbe asserted with a sensitivity selector 89. The selector 89 could be anynumber of different input types, potentiometer dial or knob withmultiple settings, switch with two settings, etc. The state of thesignal output by selector 89 is monitored by the processor 74 todetermine the user's desired setting. Based on this setting, processor74 determines when the signal output by the detection coil reaches thelevel at which the alarms should be asserted. This threshold adjustmentreduces the assertion nuisance alarms due to the presence of foilpackages or low metal content single use disposable items in the wastestream.

In some embodiments, the threshold of metal detection can be set suchthat the audible alarm does not sound until the metal content signal isabove a predetermined level, such as at a level that would illuminateall three segments 87 of the light bar 85. So, the light bar 85 showsthe user the relative metal content, but the alarms are only assertedwhen an article with sufficient metal to cause all three light segmentsof the level indicator to be illuminated. When two or less segments 87are illuminated, there is no audible alarm. The processor 74 may includea counter (not shown) that counts the number of objects that arediscarded in each segment category, e.g., number of objects thatilluminate one segment 87, two segments 87, etc. The processor 74 thenstores the information for later reporting. The reporting can be used toadjust the system settings to minimize improper discarding of objects,while minimizing inconvenience to personnel. The illuminated lightsegments can be used as a gage for the users to determine what level toset the alarms. For example, if a reusable scalpel handle when passed bythe metal detection coils illuminates two segments 87, the user candecide to set the alarms to detect the reusable scalpel handle.

A battery 80 powers the components internal to the cart 42. In mostversions of the invention, the battery 80 comprises a set ofrechargeable cells. Not illustrated is the voltage regulator(s) thatoutput signals at the potentials required by the power consumingcomponents integral with the cart 42. Also not illustrated are all theconnections from the battery 80 to which the power sourced by thebattery 80 is applied. These rechargeable cells can be charged with abuilt-in charger, or alternately charged with an independent charger;neither of the chargers are shown in the figures.

Also internal to the cart 42 is a receiver 82. The receiver 82 isconnected to the second coil 72 to convert the signals developed acrossthe second coil 72 into a form in which they can be processed byprocessor 74. The signal produced by transducer 55 is also applied toprocessor 74 as in input signal. Not illustrated are any amplifiersneeded to amplify the signal from the transducer 55 prior to applicationto the processor.

As described above, and in U.S. Provisional App. No. 60/980,954, coil 83may also form part of the circuit internal to the cart 42. The coil 83is a coil configured to receive energy that is inductively transmittedto the cart 42. As described above, the cart 42 may incorporate featuresfor trash compaction and may be periodically placed in a compactor (notshown) that compresses the waste in the bag 54. When the cart 42 is sopositioned, a current is sourced from the compactor to the cart 42 torecharge the batteries 80. An AC/DC circuit 84 is shown as beingconnected between coil 83 and the battery 80. The AC/DC circuit 84converts the AC signal developed across coil 83 into a DC signal thatcharges the batteries 80.

Processor 74 monitors the signals output by the transducer 55 and coil72. The processor 74 monitors the signal that develops across the coil72 to determine if there is rapid change in the signal. FIG. 4illustrates steps of metal detection and alarm. Step 110 of FIG. 4represents the continual monitoring of the signal from coil 72, themetal detect sensor. Step 111 represents the continual monitoring of amanually actuated alarm reset switch 126 (FIG. 4) the purpose of whichis discussed below

Processor 74 compares the signal output by coil 72, the signal obtainedin step 110, to a reference level. Again, the reference level is setbased on the user-entered setting of sensitivity selector 89. Based onthe comparison, represented by step 113, the processor 74, determineswhether or not the sensor has generated a signal indicating it is likelythat metal has passed through the frame 50 into the bag 54. In someversions of the invention, the sensor signal that is analyzed is anaverage signal. The average may be taken over a period ranging from 10microseconds to a second. The comparison may be to an average signal toreduce the likelihood that, due to noise in the sensor signal, processorincorrectly interprets a change in signal strength as indicating thepassing of metal in the bag 54. The loop back from step 113 to step 110indicates that steps 110, 111, 112 and 113 are continually executed.

If the analysis of step 113 indicates that the presence of metal hasbeen detected, in step 114 processor 74 actuates both the audio alarmand the light alarm. This means enunciator 75 and lights 79 and/or 87are actuated. After a set time, as represented by step 115, processornegates the assertion of the audio alarm. This period is typically under10 seconds and more typically less than 5 seconds. While processor 74deactivates the enunciator 78, the processor does continue to assert thecontrol signals that keep lights 79 and/or 87 actuated.

Processor 74 does however, based on the monitoring of the alarm resetswitch 126 of step 111, in a step 116, evaluate whether or not theswitch 126 is actuated. Upon determining that the switch 126 has beenactuated, in step 117, the processor 74 asserts the signals the resultin the turning off of the lights 79 and/or 87, the negation of the lightalarm.

FIG. 3 illustrates steps of weight detection and alarm. The signaloutput by transducer 55 is related to the weight of the waste containedin the bag 54. When the cart 42 is in use, the processor 74 continuallymonitors the transducer output signal, as illustrated by step 102. Asdescribed above, the processor also continues to monitor whether or thealarm switch 126 is actuated, in FIG. 3 called out as step 103.Processor 74 compares this signal received from transducer 55 to areference signal level representative of a preferred maximum weight forthe bag 54 and its contents, step 104. In the event the comparison instep 104 shows that the bag is not yet full, the above-describedmonitoring continues.

At times health care workers would be applying external loads that couldbe registered by the weight transducer 55. For example they could stepon the lower platform or be manually compacting the waste in order toget more waste into the bag. To prevent false alarms for this condition,the processor 74 could, in step 104, wait to receive two or moresubsequent signals from the transducer 55 that indicate the maximumweight has been exceeded. Only if this event occurs does the processor74 determine that the cart is in a state in which bag 54 contains weightat or above the preferred maximum level.

If the comparison of step 104 indicates that the bag 54 and its contentsare above the preferred maximum weight, processor 74, in step 106,asserts an alarm. As with metal detection, the enunciator 75 assertsboth the audio and light alarms, step 105. The audio alarm isdeactivated after a short time, step 106. The actuation of lights 79and/or 87 continues until it is determined in step 107, alarm resetswitch 126 is depressed. At that time, in step 108, the light alarm isnegated.

Referring back to FIG. 1, the cart 42 of the system 40 of this inventionis prepared for use by fitting the bag 54 to the cart 42. Immediatelyprior to the medical or surgical procedure to be performed, the cart 42is activated. This activation means that the signal generator 76 isactivated by control switch 124 and the processor 74 actively monitorsthe signal across coil 72 and the pressure sensed by transducer 55.During the medical/surgical procedure, waste is placed in the bag 54 ina conventional manner.

The assertions of both the audible and light alarms of step 114 providethe medical/surgical personnel with the notice that metal has enteredthe bag 54. The alarm serves as a cue so that these personnel can verifythat the object discarded was not a reusable object that wasinadvertently discarded. If the investigation indicates the object wasinadvertently discarded, it can then be promptly retrieved beforeadditional waste is piled on top of it.

Alarm reset switch 126 can be a foot pedal movably mounted to the base44 of the cart 42. By using the foot pedal, the user does not need tobreak sterility during the medical or surgical procedure to shut off thealarm. Alternately, a shut-off switch can be added to this embodiment.The additional shut-off switch can be located in the top structure ofthe cart 42 on the opposite side of switch 126. This switch can be addedto the outside of front web 60 for example. This position allows thenon-sterile circulator in the operating room a more convenient locationto control the alarm particularly when the foot switch 126 is facing thesterile surgical field.

Embodiments described herein describe metal detection working at thepoint of disposal. During use, these point of disposal metal detectionsystems offer real time information that benefits the ability of someoneto discover if reusable medical equipment is inadvertently discarded. Asmentioned, there are single use disposable instruments that containmetal and are discarded after a single use. The waste collection systemof this invention provides real time information and allows the user toreview the real time information provided to his/her expectation as towhat should happen when disposing of waste. For example, a smallreusable electric power tool used in surgery is clamped on a disposablesurgical drape. Post use, the drape may be rolled up for disposal andthe tool is rolled into the drape. When the rolled up drape is placed inthe appropriate container, the point of disposal metal detection systemof this invention asserts an alarm indicating to the medical worker thatthere is a metal object in the rolled drape. Since the worker'sexpectation was the only item being disposed of was a drape, theassertion of the alarm alerts the worker that it is now appropriate toinvestigate the drape in order to determine if another objection isinadvertently entrained in the drape. The information provided inconjunction with the timing of that information allows the worker toefficiently recover and prevent inadvertently discarding a valuablepiece of reusable equipment. In another example, the worker isdiscarding a single use battery powered irrigation system containing ametallic motor. When the worker discards the irrigation system, theirexpectation was that the alarms would be set off by the metal detectionsystem. Since the alarms met the expectation, the worker could simplyreset the alarms without having the need to investigate or dig throughthe waste container.

Alarms described in these embodiments can be controlled by the processorin different configurations and sequences. For example, the metaldetection system could be configured with only a visual or only anaudible alarm. Visual alarms can be in the form of the light 79 or setof lights 79. The audible alarms can be in the form of the enunciator 75which can be formed from a piezo-electric buzzer or a more elaboratespeaker (not shown). In one preferred embodiment, the metal detectionsystem could be configured with both an audible and visual alarm. Thesealarms can be mechanized to provide the important alerting functionwhile minimizing the distraction they cause. For example, when the metaldetection system processes the signal and determines it is appropriateto alarm, both audible and visual alarms could be fired. In thisexample, the audible alarm could sound for a finite time, say 1 second,and then automatically turn off. The lights could stay on until a workerinvestigates the waste and then actuates the alarm reset switch 126 orother shut-off switch. This mechanization of alarming allows the workerto continue performing some other critical work, like performing amedical procedure, without forgetting to investigate the waste formetallic equipment until there is a more convenient time for thatinvestigation.

During the course of the procedure, the contents of the bag 54 increasein weight and volume. The processor 74, per the steps of FIG. 3, alsomonitors the weight of the bag 54. If the bag starts to becomeexcessively weighted down, the assertions of the alarms provide noticethat it may be appropriate to replace or empty the bag.

Eventually, there is a point in the procedure at which bag 54 is readyfor closure. For a particular bag this may be because, as a result ofthe execution of step 104 it is determined that the bag 54 is full.Alternatively, it may be that the actual medical/surgical procedure iscomplete and the bag 54, while not full, is ready for short-term storageand transport.

Referring to FIGS. 5 and 6, an alternative system 240 of this inventionincludes a cart 242 is shown with a pre-detection apparatus fordetecting metal-containing objects in batches before being dumped in thebag 54. These batches contain a volume of waste that is only a portionof the entire volume of waste ultimately discarded in the bag 54.Without the pre-detection apparatus, when metal-containing objects aredetected by the previously described system 40, the user must sortthrough existing waste already deposited in the bag 54 to find theobjects. By detecting the waste in batches, i.e., batch processing, theamount of waste that requires inspection to find the metal-containingobjects is much smaller. This makes it easier to sort through andreduces exposure to harmful contaminates, offensive odors, broken glassor other objects that could be a hazard to the individual required tosort through the waste stream.

The pre-detection apparatus of FIG. 5 includes a hopper 200 rotatablyconnected to the frame 50. Hopper 200 includes a support platform 202, apair of sidewalls 204 extending upwardly from the support platform 202,and a rear wall 203 extending upwardly from the support platform 202.The rear wall 203 interconnects the sidewalls 204 to form a temporarystorage space 205 for each batch of waste to be processed. A pair ofhinges 206 pivotally connects the platform 202 to the frame 50. Thehopper 200 pivots about the hinges 206 between a load position and adump position. The user grasps a handle 208 on the hopper 200 to movethe hopper 200. An arm 210 extends perpendicularly in a cantileveredfashion from the leg 48 to support the hopper 200 and each batch load.

In this embodiment, a second pressure-sensitive transducer 211 isdisposed on the arm 210 to determine the weight of each batch of waste.This information can be used to develop a metal content-to-weight ratioor factor. Accordingly, the alarm could be based on this factor. Forinstance, the segments 87 on the light bar 85 could be selectivelyilluminated based on this factor being above a predetermine level.

In this embodiment, the coils 70, 72, 73 are disposed in the sidewalls204 to detect metal that may be present in each batch. The metaldetection arrangements previously described could be utilized, such asthe concentric coil arrangement, which could be placed in the platform202. It should also be appreciated that any metal detection arrangementcould be employed with any of the pre-detection features describedherein.

During use, objects intended for disposal in the bag 54 are first placedon the support platform 202 of the hopper 200. Support platform 202 thusfunctions as a loading station for the waste. Metal detection continueswhile each object is loaded into the hopper 200. When metal is detected,the alarm is actuated as previously described including the audiblealarm, visual alarm, or both. By using the hopper 200, the worker hasless waste to sift through when metal is detected. Likewise, the batchload has a relatively small depth such that the user can often visuallyinspect the waste when the alarm is actuated to find themetal-containing object that tripped the alarm. Once the user issatisfied that material in the hopper 200 is to be discarded, the usergrabs the handle 208 and moves the hopper to the dump position to allowgravity to transfer, dump, the batch in the bag 54.

Referring to FIGS. 5 and 7, a separate disposable covering 212 protectsthe hopper from being soiled by the waste. The covering 212 defines asleeve that slips down over the rear wall 203 and sidewalls 204 of thehopper 200. The sleeve includes a plurality of panels 214 sealedtogether to form an air-tight barrier that closely follows the shape ofthe hopper 200. FIG. 8 shows a bag 216 with an alternative protectivecovering 218 for the hopper 200 integrated with the bag 54 previouslydescribed.

Referring to FIG. 9, an alternative system 340 of this invention with apre-fill structure includes a platform 300 pivotally connected to theframe 50. A pair of hinges 302 pivotally connects the platform 300 tothe frame 50. The platform 300 is movable between a stowed position inwhich the platform folds down to reduce the overall footprint of thecart 342 and a load position (shown in FIG. 9).

A disposable tray 304 (or reusable tray with protective covering) isdisposed on the platform 300 when in the load position for receivingwaste intended for depositing in the bag 54. Platform 300 functions asthe loading station.

A detector frame 306 slides along the platform 300 either manually orautomatically to scan the tray 304 when full to determine if anymetal-containing objects not to be discarded are present. The detectorframe 306 includes four interconnected members 308, 310, 312, 314including opposing top 308 and bottom 310 members and opposing left 312and right 314 side members. The side members 312, 314 are notched toslidably receive the platform 300. The coils 70, 72, 73 are disposed inthe side members 312, 314 to detect any metal-containing objects.

In embodiments in which scanning is automatic, the platform 300 includesa second pressure-sensitive transducer 316 to determine the weight ofthe batch of waste on the tray 304. When the batch reaches apredetermined weight or metal content-to-weight factor, the detectorframe 306 moves across the tray to detect any metal-containing objects.

A drive assembly 318 moves the detector frame. The drive assembly 318includes a motor 320 and a drive screw 322. The drive assembly 318further includes a drive nut 324 fixed to the bottom member 310 toreceive the drive screw 322. Preferably, the processor 74 actuates themotor 320 upon the batch reaching the predetermined weight or factor.Alternatively, the processor actuates the motor 320 periodically to scanthe batch with the drive assembly 318 re-setting the detector frame 306to the start position (see FIG. 9) at the end of each scan. The motor320 could also be push-button controlled in manual embodiments. A manualwand metal detector 326 could also be used to scan the batch of wastebefore dumping in the bag 54.

In a similar embodiment shown in FIG. 10, a detector frame 330 is fixedto the platform 300 of the cart 42 and the user passes the tray 304through the detector frame 330 prior to disposal. When the user issatisfied that the detected objects were not inadvertently discarded,the user manually dumps the tray in the bag 54.

Referring to FIG. 11-13, another system 440 with a pre-detectionapparatus is shown. In this embodiment, a bag-constraining device 400chokes the bag 54 just below the frame 50 to create a batch volume inthe bag 54. The bag-constraining device 400 includes an elastic band 402placed over the bag 54 at the desired position. In its normal state, theelastic band 402 chokes the bag 54 to prevent the transfer of waste fromabove the band to below the band until each batch is processed.Typically, the batch volume is sized such that two to ten batches areprocessed for each bag 54.

The bag-constraining device 400 also includes a plurality of non-metalloops 404 each of which extends around the band 402. A flexible,non-elastic cable 406 extends from each of the loops 404 and isconnected to the loops 404 with hooks 408 or Velcro™ or other releasableconnector. A plurality of motor/pulley assemblies 410 operate to windeach of the cables 406 on pulleys 412 (see FIG. 13). When winding thecables 406 on the pulleys 412, the elastic band 402 is pulled at fourequidistant positions around the band 402 to expand the band 402 andunconstrain the bag 54 to release the batch contents.

During operation, the upper portion of the bag 54, when in theconstrained state, functions as the loading station in which thematerial intended for disposal is initially deposited. The height of thematerial in this loading station is monitored by an optical sensor 414mounted in one of the webs 60, 62, 64, 66. This material heightmeasurement serves as an approximation of the volume of waste at thestation. Once the height of the waste reaches the optical sensor, theprocessor 74 determines the cumulative content of the metal sensed inthe batch of material at the loading station. If the calculated metalcontent is within an acceptable limit, processor 74 allows the materialto fall into the bottom section of the bag 54. Processor 74 allows thisevent to occur by actuating the motor/pulley assemblies 410 to expandthe elastic band 402 and release the batch load of waste. Once the loadis released, the motor/pulley assemblies 410 reverse direction and theelastic band 402 is allowed to re-choke the bag 54 in preparation for anew batch of waste. It should be appreciated that a manual push-buttoncontrol could also be used to actuate the motor/pulley assemblies 410.Coils 70, 72, 73 are disposed in the frame 50 to detect metal in eachbatch and actuate the alarm as previously described.

The bags 54 can be assembled and provided to the facility in which theprocedure is being performed with the band 402 and loops 404 alreadyattached to the bags 54 so that the user has only to connect ordisconnect the hooks 408 to the band 402 when replacing bags 54. Withthe band 402, a smaller footprint is provided to take up less floorspace than other embodiments of the invention.

Referring to FIGS. 14-16, another system 540 including a cart 542 isshown with an alternative bag-constraining device 500. Here, the band402 is replaced with a pair of pinch bars 502 to create the batch volumein the bag 54. A pair of motors 504 are mounted to an underside 506 ofcorners of frame 550. Each motor 504 operates one of the pinch bars 502to close and pinch the bag 54 just below the frame 550. Coils 70, 72, 73are disposed in the frame 550 to detect metal. A second pressuretransducer 510 is disposed on one of the pinch bars 502 to detect thebatch weight. The processor 74 assesses the weight and the metal contentof the batch, and if acceptable, the pinch bars 502 are movedautomatically to release the batch into the lower portion of the bag 54.

In this embodiment, the frame 550 is modified by removing the front web60 and corner blocks 52. Instead, the frame 550 of FIGS. 14-16 includesonly a rear web 562 and side webs 564, 566. The lights 79 are mounted tothe end of the side webs 564, 566 and on a display board 518. FIG. 15shows a bag 520 configured to fit onto the cart 542 shown in FIG. 14.Like the bag 54 of FIG. 1, bag 520 is formed of two main rectangularpanels 522 sealed together at their bottom and side edges. The bag 520further includes a pair of sleeve panels 524 sealed at their top edges551 and bottom edges (not identified) to the outside of the main panels522 at the top of each of the main panels 522 and just below the top ofeach of the main panels 522 to define sleeves for sliding onto the sidewebs 564, 566. The sleeves protect the side webs 564, 566 from dust anddebris during use.

FIG. 16 shows another bag with a second pair of sleeve panels 530 sealedto the outside of the main panels 522 to define sleeves for sliding ontothe pinch bars 502. The second pair of sleeve panels 530 are also sealedalong their top and bottom edges across each of the main panels 522. Thesleeve panels 524, 530 have a length equal to a width of the main panels522 such that the top and bottom edges of the sleeve panels 524, 530 aresealed completely across the main panels 522, while the side edges ofthe sleeve panels 524, 530 remain unsealed to provide the sleeves forslipping on the side webs 564, 566 and pinch bars 502.

In the versions of the invention illustrated with respect to FIGS.14-16, as with the versions of the invention illustrated in FIGS. 11-13,the top of the bag, when in the constrained state, functions as theloading station on which the material deposited for disposal isinitially placed.

Referring to FIG. 17, another system 640 with a cart 642 with abag-constraining device 600 is shown. In this embodiment, thebag-constraining device 600 includes a pair of doors 602 pivotallymounted to the side webs 564, 566. The doors 602 are moveable betweendump positions and load positions. Each door 602 is generally planar toform a bottom of the frame 50 when in the load position. A pair ofmotors 604 are mounted to an underside of the rear corners of the frame50. Each motor 604 rotates one of the doors 602 between the dumpposition and the load position. In the load position, the doors 602close an opening through the frame 50 and pinch the bag 54 therebetween.After a new bag 54 is placed on the cart 642, the motors 604automatically or manually move the doors 602 to the load position.

Once in the load position, the cart 642 is ready for batch loading.Coils 70, 72, 73 are disposed in the frame 50 to detect metal. A secondpressure transducer 610 is disposed on one of the doors 602 to detectthe batch weight. The doors 602 are moved automatically upon the batchreaching a predetermined weight or metal content-to-weight factor. Thebatch loading, alarming and dumping processes proceed in this embodimentas described in the previous embodiments including both manual andautomatic operations.

FIGS. 18-20 show another system 740 with a cart 742 with abag-constraining device 700. In this embodiment, the bag-constrainingdevice 700 pinches the bag 54 just below the frame 50 and heat seals thebag 54 at this location to create a batch volume for the waste of only aportion of the total volume of the bag 54. Preferably, two to tenbatches are processed in each bag 54.

Referring specifically to FIG. 19, the bag-constraining device 700includes a pair of pinch bar assemblies 702 for pinching the bag 54 justbelow the frame (frame not identified). Each pinch bar assembly 702includes a horizontal member 706 and a vertical member 708 extendingdownwardly from the horizontal member 706. A rectangular key 710 isdisposed on each opposing end of the horizontal member 706 and extendsupwardly from each end through an elongated slot in the underside of thefront 760 and rear 762 webs (slots not illustrated). A nut 714 is fixedto each of the keys 710. A drive screw 716 is mounted in each of thefront 760 and rear 762 webs to drive the nuts 714 while the keys 710 inthe slots 712 prevent the nuts 714 from rotating. The nuts 714 travelalong the drive screw 716 to move the pinch bar assemblies 702 from thedump position to the load position. The drive screw 716 can beconfigured such that one half of the drive screw 716 has threads in onedirection and one half with threads in an opposite direction. Drivescrew 716 thus moves nuts 714 of pinch bar assemblies 702 toward oneanother when the drive screw is rotated in one direction and away fromone another when rotation is reversed.

Referring to FIG. 20, the base 744 of the cart 742 includes a movableplatform 718 for supporting the bag 54 and its contents. A pair of driveassemblies 720 move the movable platform 718 upwardly along tworectangular legs 748. Each drive assembly 720 includes a motor 724mounted to the base 744 and a drive screw 726 rotatably supported ineach of the legs 722. The movable platform 718 includes a pair of drivenuts 728 fixed to and extending from opposing sides of the movableplatform 718. Keys 730 connect the nuts 728 to the movable platform 718.The keys 730 are inserted into elongated slots 732 in the legs 748 totravel along the slots 732 during adjustment that is similar to thepinch bar assemblies 702.

When a bag 54 is first placed on the cart 742, the pinch bar assemblies702 are moved to the load position to constrain the bag 54 below theframe 750 and the movable platform 718 is raised to a position justbeneath the pinch bar assemblies 702. When the pinch bars 702 close, theopposed sections of the bag above the pinch bars is become a loadingstation. Material for disposal is placed on these sections of the bag54. The coils 70, 72, 73 may be disposed in side webs 64, 66 aspreviously described, or the coils 70, 72, 73 may be disposed in thehorizontal members 706 of the pinch bar assemblies 702. Metal detectionand alarms occur as previously described in this embodiment.

Once the initial batch of waste is processed, the pinch bar assemblies702 either manually or automatically move from the load position to thedump position. The movable platform 718 then supports the batch load andis lowered until the pinch bar assemblies 702 are disposed above thebatch load.

Heat-sealing coils 734, 736 are disposed in the vertical members 708 ofthe pinch bar assemblies 702. The vertical members 708 come together inthe load position for the second batch of waste and the processor 74then actuates the heat-sealing coils 734, 736 to create a seal at apinched section of the bag 54 above the initial batch load.

Thus, the bag 54 is sealed above and below the batch load to containfluids and reduce odors from emanating out of the bag 54. In thisembodiment, the initial batch load is stored at a bottom of the bag 54and the bag 54 is heat sealed above the batch load. Subsequent batchesare stored on top of the last. The movable platform 718 may include thetransducer 55 so that the processor 74 can determine an overall weightof the bag 54. Alternatively, a second transducer 755 on one of thepinch bar assemblies 702 may be used to determine batch weights andtotal weight by adding individual batch weights. The second transducer755 can also be used for determining, by the processor 74, when eachbatch is finished processing using weight or factor values.

In other embodiments, heat sealing could be replaced by batch separatorsthat are either manually or automatically placed in the bag 54 toseparate batch loads, e.g., cardboard inserts (not shown), or the bags54 could be configured with integral flaps (not shown) that fall intoplace over each batch after each batch is processed.

Referring to FIG. 21, an assembly 840 with a cart 842 similar to thatshown in FIG. 10 is shown with a conveyor belt 800 mounted to frame 50so as to be located adjacent the open end of the bag 54. Conveyor belt800 thus functions as the loading station on which the material fordisposal is placed. A supplemental frame 802 with metal detectingsensors is located over the conveyor belt 800. A motor 804 andmotor-driven roller 806 drives the conveyor belt 800 around a secondroller 808. The material deposited for disposal initially passes acrossthe metal-detecting sensors located in frame 802. From frame 802,conveyor belt 800 transfers the material into the open end of the bag54. If, however, the sensors assert signals indicating the potentialpresence of the metal, the processor controlling assembly 840 assertsone or more alarms to provide notice of the possibility of an object inthe waste stream that should not be disposed. The processor alsodeactivates the motor 804 to stop the object from being dumped into thebag. This gives personnel the opportunity to inspect the object todetermine whether or not the object should be disposed. This embodimentcould also include doors (not shown) to open and close access to the bag54. In this embodiment, waste is placed on the conveyor belt whichclosely simulates the process of throwing trash directly into a bag.This embodiment closely matches what is traditionally done in medicalfacilities today, namely discard trash at the point of generation andtherefore causes minimal disruption to the medical procedure.

-   -   Referring to FIGS. 1 and 22, a bag-tensioning mechanism 900 is        shown. The bag-tensioning mechanism 900 includes a knob 902        rotatably mounted to and supported in one of the side webs 64,        66. The knob 902 includes a base plate 904 in rotating abutment        with an outer side face 906 of, arbitrarily, side web 64. An        outer grasping head 908 is spaced from the base plate 904 by a        pin-like shaft 910. A bag catch 912 is mounted to the base plate        904 and extends outwardly therefrom for catching a sub-section        of the peripheral section 51 of the bag 54. The bag catch 912 is        preferably a pin. While not identified, it is seen that the pin        forming catch 912 has an enlarged head that is spaced from the        base plate 904. When bag 54 is fitted to the cart 42 the        sub-section of the peripheral section 51 of the bag is fitted        around this pin head to hold the peripheral section 51 of the        bag 54 to the catch 912.

Referring specifically to FIG. 22, inside a hollow space of the side web64, the knob 902 includes a ratchet plate 916. The ratchet plate 916 isspring loaded by a spring 918 so that as the ratchet plate 916 isrotated, the spring tension force increases. A spring-biased pawl member920 ratchets along notches in the ratchet plate 916 to hold the ratchetplate 916 against the spring tension force. Pawl member 920 also holdsthe ratchet plate 916 in position in opposition to the external forcesgenerated—when, as described below, the peripheral section 51 of the bagis placed in tension. A release push button 922 is arranged to lift thepawl member 920 when pressed and release the ratchet plate 916. Whenthis occurs, the ratchet plate 916 and knob 902 rotate back to theirinitial position under the spring tension force placed on the ratchetplate 916 and knob 902 by the spring 918.

Bag 54 is fitted to cart 42 by folding the peripheral section 51 of thebag over the outer surface of the frame 50 including the outwardlystepped surfaces of corner blocks 52. One sub-section of the folded overperipheral section 51 of the bag 54 is routed around the shaft 910 andwrapped or hooked about the bag catch 912.

A second sub-section of the bag peripheral section that is located 2.5to 5 cm from the top of the bag is wrapped about the bag catch 912. Theuser rotates the knob 902 by grasping the grasping head 908 of the knob902 to twist the peripheral section 51 of the bag 54 that is wrappedaround the catch around shaft 910. This twisting places the bagperipheral section 51 in tension around the outer surface of cart frame50. This tension secures the bag 54 by increasing the friction betweenthe bag 54 and the frame 50. The tension also the hoop tension below thecorner blocks 52 thus working in combination with the corner blocks 52to secure the bag peripheral section 51 around the outside of the sidewebs. The above described pawl assembly functions as a lock assemblythat releasably holds catch 912 in this position, a bag tensionposition, so as to maintain the tension on the bag 54. Dislocating thebag from this tensioned position requires the bag 54 to stretch over thecorner blocks 52. To remove the bag 54, the user presses the releasebutton 922. This results in the displacement of pawl member 920 awayfrom ratchet plate 916. This force imposed by spring 918 and the tensionforce of the bag transferred to catch 912 then rotate the catch back tothe initial bag load position of the catch. This results in theuntwisting of the bag around shaft 910. The untwisting slacks off thetension on the bag peripheral section 51. Bag 54 can now be removed fromthe cart 40. Cart 40 is now ready for a new bag 54.

Referring to FIG. 23, an alternative bag-tensioning mechanism 1000 isshown. In this embodiment, two routing posts 1002 with enlarged heads1004 are mounted to one of the side webs 64, 66. A spring-loaded slidingpin 1006 with enlarged head 1008 acts to tension the peripheral 51 ofthe bag 54. The pin 1006 is slidably mounted through an elongated slot1010 in a housing 1012 mounted to an underside of the side web 64. Pin1006 thus engages in translational motion relative to said posts 1002. Aspring 1014 is mounted to the pin 1006 at one end and to the housing1012 at an opposite end. The user first positions the sliding pin 1006to a load position by overcoming the spring tension (as shown in FIG.23). The peripheral section 51 of the bag 54 is routed between therouting posts 1002 and over the enlarged head 1008 of the sliding pin1006. Pin 1006 functions as the catch of this bag tensioning assembly.The user then releases the sliding pin 1006. Spring 1014 then displacessliding pin 1006 back to the initial bag tension position. The portionof the peripheral section disposed over sliding pin 1006, translateswith the pin. This places that portion of the bag disposed around one ofposts in tension. As a result, the peripheral section 51 of the bag 54is tensioned so as to hold the bag 54 around the outer surface of theframe and the corner blocks 52. Spring 1014 functions as the lockingmember that, in opposition to the tension force applied by the bagperipheral section 51, holds pin 1006 in bag tension position. To removethe bag 54, the user re-positions the sliding pin 1006 into the loadposition and unhooks the bag 54 from the sliding pin 1006. The enlargedheads 1004 of routing posts 1002 and head 1008 of pin 1006 keeps theperipheral section 51 of bag 54 from slipping off of these components.

Referring to FIGS. 24A, 24B and 25, another alternative bag-tensioningmechanism 1100 is shown. Here, two routing posts 1102 with enlargedheads 1104 are mounted to one of the side webs 64, 66. A pair ofmounting brackets 1112 are fixed to the side web 64. A pair of rubbergripping pads 1106 are mounted to the brackets 1112 beneath the routingposts 1102. The pads 1106 are fixed at one end to the brackets 1112 andextend to a cantilevered end such that the cantilevered ends of the pads1106 abut one another. The peripheral section 51 of the bag 54 is routedbetween the routing posts 1102 and between the cantilevered ends of thepads 1106. The pads 1106 flex downwardly as a portion of the peripheralsection 51 of the bag 54 is pulled between the pads 1106. Once enoughtension is placed on the bag 54 to hold the peripheral section 51 aroundthe outer surface of the frame 50, the user ceases pulling the bag 54through the pads 1106. The pads 1106 then release toward their normalposition horizontally opposed to one another and pinch the bag 54between the pads 1106 to hold the bag 54 in place as shown in FIG. 24B.Pads 1106 collectively function as a catch that holds bag 54. The pads1106 and brackets serve as a one-way holding mechanism to maintain thebag peripheral section 51 tension applied by the user. To release thebag 54, the user pulls the bag horizontally, parallel to the pads 1106edges until the bag peripheral section 51 is clear of the pads 1106.

In the variation shown in FIG. 25, springs 1110 extend from projections1114 fixed to the web 64. The springs 1110 movably connect the brackets1112 to the projections 1114. The springs 1110 urge the pads 1106upwardly as the user pulls the bag through the pads 1106 downwardly tofacilitate mounting of the bag 54.

FIG. 26 shows another bag-tensioning mechanism 1200. In this embodiment,two swing arms 1202 are pivotally mounted to the rear web 62 of theframe 50. Torsion springs 1204 are positioned over pins 1206 thatpivotally hold the swing arms 1202 to the rear web 62. The swing arms1202 are L-shaped. Springs 1204 place a force on arms 1202 that normallyhold the arms away from rear web 62. In use, the periphery 51 of the bag54 is rolled over the frame 50 and the swing arms 1202 while the swingarms 1202 held against the rear web 62 and against the spring bias ofsprings 1204. The swing arms 1202 are then released. The force of thesprings 1204 moves the arms 1202 outwardly. The outward movement of thearms against the bag places a tension on the periphery 51 of the bag 54.To remove the bag 54, the swing arms 1202 are again held against theframe 50 and the bag 54 is removed from the frame 50 and swing arms1202.

In other versions of the invention not shown, a supplementalidentification system could be used in combination with metal detectionto prevent re-usable objects from being discarded, or to prevent objectsfrom being discarded in the wrong bag. Referring to FIG. 1, theidentification system includes RFID tags 90 (see sample object beingdiscarded) placed on all objects used during the course of a medical orsurgical procedure. A reader 88 mounted to the frame senses the RFIDs asthey pass by the reader 88 while discarded. In FIG. 1, the reader 88 ismounted to the rear web 62 and an object with RFID 90 is shown passingthe reader 88. The reader 88 sends corresponding signals to theprocessor 74 when each RFID is sensed. The processor 74 then looks upthe RFID in look-up tables to determine if the object is to be discardedor if it is reusable. If it is not to be discarded, the alarm isactuated. A different alarm could be used to clearly indicate that theobject was incorrectly discarded.

The processor 74 could also be wirelessly connected to a centralinventory control system (not shown) to monitor inventory and orderequipment, tools, accessories, etc. as the objects are discarded. Atleast two acceptable modes of wirelessly transmitting data from theprocessor to the inventory control system are Infrared or Radiofrequency. In one example, the packaging materials of a single usedisposable product can contain the RFIDs and the reader 88 transmits thesignal to the central inventory control system indicating the packagehas been opened and needs replacement.

The data from the RFID tag and other metal detection information can bewirelessly transmitted to other management systems that may benefit fromsuch information.

During the course of a procedure the waste is deposited in thecorresponding bags 54 (e.g., white, red, green, yellow, etc.) secured toseparate carts 42. The carts 42 are typically positioned in theoperating room or other space in which waste are generated. Acirculating nurse, or other individual that receives the waste from theperson depositing it, is responsible for initially categorizing thewaste and placing it in the appropriate cart 42. When a bag 54containing either conventional waste, red bag waste, green waste orradioactive waste is at or near capacity, it is sealed. At that time,the bag 54 is transported to a loading dock for eventual transport to awaste processing facility.

Obviously many modifications and variations of the present invention arepossible in light of the above description. Thus the features of thedifferent embodiments of this invention may be combined. Also, not allfeatures in each embodiment of the invention may be necessary to providethe advantages and benefits of the described embodiments. Similarly, theshapes of the components may be different from what has been described.For example, while the frame from which the bag is suspended isgenerally shown as rectangular, it need not always have this shape. Insome versions of the invention the frame may be circular or oval. In notall versions of the invention is it necessary to have a null coil aspart of the metal detection assembly. Likewise other means than thedisruption of magnetic fields may be used to sense whether or not thereis metal in the object being subjected to disposal.

While this description is directed to particular embodiments, it isunderstood that those skilled in the art may conceive of modificationsand/or variations to the specific embodiments shown and describedherein. Any such modifications or variations, which fall within thepurview of this description, are intended to be included herein as well.It is understood that the description herein is intended to beillustrative only and is not intended to be limited.

What is claimed is:
 1. A portable cart for collecting medical waste in abag, the bag having an open end and a base opposite the open end, saidcart including: a mobile base; a frame attached to said mobile base thatis located above said mobile base, said frame configured to hold the bagto said frame so that the open end of the bag is adjacent to andaccessible from said frame; a loading station attached to said mobilebase or said frame so as to be located adjacent the open end of the bagfor receiving an object for disposal; a sensor for detecting if theobject for disposal contains metal, said sensor being located adjacentthe loading station for determining if the objects on said loadingstation contain metal; and a transfer mechanism located adjacent saidloading station and the bag, said transfer mechanism having at least onemoveable component that, when actuated, transfers objects on saidloading station into the bag.
 2. The portable cart of claim 1, whereinsaid loading station is a platform located adjacent the frame.
 3. Theportable cart of claim 2, wherein said platform is secured to said frameby at least one hinge so that said platform is able to move between aload position in which objects placed on said platform are detectable bysaid sensor and a dump position in which gravity causes objects on saidplatform to move into the bag, so that said platform and said hingecollectively function as said transfer mechanism.
 4. The portable cartof claim 1, wherein said loading station and said transfer mechanismcollectively include a conveyor mounted to said frame adjacent the openend of said bag that, when actuated, transports objects on said conveyorinto the bag.
 5. The portable cart of claim 1, wherein said loadingstation and said transfer mechanism collectively include at least onedoor moveably attached to said frame over the bag, said door having afirst position in which said door holds objects placed thereon so thatthe objects can be detected by said sensor and a second position inwhich said door moves to allow objects placed thereon to fall into thebag.
 6. The portable cart of claim 1, wherein said loading station andsaid transfer mechanism collectively include an assembly attached tosaid mobile base or said frame that selectively holds a section of thebag above the bag base closed and that opens the closed section of thebag, so that the closed section of the bag, when closed, functions assaid loading station.
 7. The portable cart of claim 6, wherein saidassembly that holds the section of the bag closed includes: an elasticmember that extends around at least a portion of the bag between the bagopening and the bag base, said elastic member configured to normallyhold a section of the bag above the elastic member closed; and a releaseassembly that is attached to said elastic member for expanding saidelastic member so that the expansion of the elastic member results inthe opening of the section of the bag above the elastic member.
 8. Aportable cart for containing medical waste, the cart including: a mobilebase; a frame attached to said mobile base that is located above saidmobile base, said frame having an outer surface and an opening; and abag removably mounted to said frame so as to be open within the frameopening wherein said bag has a peripheral section that defines anopening into said bag and that extends over the outer surface of saidframe; and a bag tensioner mounted to said frame, said bag tensionerincluding: a first pin that is mounted to said frame that extends fromthe outer surface of said frame at a fixed location, said first pinmounted to said frame so that a first sub-section of the bag peripheralsection can be disposed against said first pin; and a catch moveablymounted to the outer surface of said frame adjacent said first pin, saidcatch being shaped to receive a second sub-section of the bag peripheralsection, wherein said catch is moveable relative to said first pin tomove between a bag tension position in which said first pin and saidcatch cooperate to place the bag peripheral section in tension aroundthe outer surface of said frame and a bag load position in which saidfirst pin and said catch do not place the bag peripheral section intension.
 9. The portable cart of claim 8, wherein said bag tensionerfurther includes a lock assembly that extends between said frame andsaid catch and that, when said catch is in the bag tension position andthe bag peripheral section is in tension, releasably holds said catch inthe bag tension position.
 10. The portable cart of claim 9, wherein saidlock assembly of said bag tensioner includes a biasing component that,in the absence of said catch being held in the bag tension position,urges said catch towards the bag load position.
 11. The portable cart ofclaim 9, wherein said bag tensioner lock assembly includes a ratchetassembly to which said catch is mounted.
 12. The portable cart of claim9, wherein said bag tensioner lock assembly includes a spring thatextends between said frame and said catch to releasably hold said catchin the bag load position.
 13. The portable cart of claim 8, wherein saidcatch is a second pin around which the second sub-section of the bagperipheral section is fitted.
 14. The portable cart of claim 8, whereinsaid catch is a second pin around which the second sub-section of thebag peripheral section is fitted and said second pin is mounted to saidframe to rotate around said first pin.
 15. The portable cart of claim 8,wherein said catch is a second pin around which the second sub-sectionof the bag peripheral section is fitted and said second pin is mountedto said frame to engage in translational motion relative to said firstpin.
 16. The portable cart of claim 8, wherein said catch is moveablymounted to the outer surface of said frame to engage in translationalmovement relative to said first pin.
 17. The portable cart of claim 8,wherein said catch is a gripping assembly that is moveably attached tothe outer surface of said frame, said gripping assembly includingadjacent members that pinch against the second sub-section of the bagperipheral section to hold the second sub-section of the bag peripheralsection.
 18. The portable cart of claim 8, wherein said catch is agripping assembly that is moveably attached to the outer surface of saidframe, said gripping assembly including adjacent gripping members thatpinch against the second sub-section of the bag peripheral section tohold the second sub-section of the bag peripheral section between saidgripping members and said gripping assembly is mounted to said frame toengage in translational movement relative to said first pin.
 19. Theportable cart of claim 8, wherein: said bag tensioner includes a secondpin that is statically mounted to the outer surface of said frame aroundwhich a third sub-section of the peripheral section of said bag isdisposed; and said catch is mounted to said frame so that the secondsub-section of the peripheral section of said bag held by said catch islocated between the first sub-section of the peripheral section of saidbag disposed against said first pin and the third sub-section of theperipheral section of said bag disposed against said second pin.
 20. Theportable cart of claim 8, wherein: said first pin is mounted to saidframe to rotate around the location at which said first pin is mountedto said frame; and said catch is connected to said first pin to rotatearound said first pin as a result of the rotation of said first pin. 21.The portable cart of claim 8, wherein said frame includes at least onestepped surface that extends outwardly from the outer surface of saidframe.
 22. The portable cart of claim 8, wherein: said frame includes atleast one stepped surface that extends outwardly from the outer surfaceof said frame; and said bag tensioner is configured to place theperipheral section of said bag in tension around at least a portion ofthe outer surface of said frame located below the at least one steppedsurface of said frame.
 23. The portable cart of claim 8, furtherincluding a metal detector and an alarm mounted to said frame, saidmetal detector configured to: determine whether or not a metal object isinserted into said bag through said frame; and if a metal object isinserted into said bag, actuate said alarm.